Saddle for spinning frames or the like



Allg- 19, 1952 L. M. co'rcHETT ET A1. 2,607,084

SADDLE FOR SPINNING FRAMES OR THE LIKE Aug. 19, 1952 1 .,M. coTcHETT ET AL Y 2,607,084

- SADDLE EOR SPINNING FRAMES OR THE LIKE Filed Jan.' 27, 194s 2 SHEETS- SHEET 2 j mi", "Inl". f 1 I/- J [12 den 2501's:

Lo-Lgz'sMCbi'fcbeZi" and RoberZ' doni/141'] [er Patented Aug. 19, 952

SADDLE lFOR. SPINNING FRAMES R. THE LIKE A y Louis M. Cotchett, Whitman, Mass., andRo'bert' Billon-'Millen Bristol, R. I.,v assignors lto -Dixon .'.Lubricating Saddle'Company', Bristol, R. I., a

corporation of Rhode Islandk Application January 27, isiafseriamo. 4ms' i Thisfinvention relates to vsaddleslorweighting thev `top lrolls of machinesfor treating vtextile bers, such as spinning and'drawing frames, and consists in improvements -in the kconstruction and arrangement thereof, particmarly to provide replaceable oilless bearings having frictionreducing and wear-resisting characteristics.

One object of the-inventionistojprovide a saddle assembly-havinga smooth, polished upper surface withoutindentationsfor oil holes. cups or the'y like whereby to 'prevent lint fromfdepositing thereon and adhering-thereto.- y

Another object is -to-rlvprovide an adjustable saddle for practicallyiuniversal use vandadapted to` accommodate the setting 'of-the rolls for a maximum range Voistaple lengths of ber from the shortesttoV the longest.

Another object is toprovide a saddle assembly constructed from sheet-'metal havingthe point of contact between the Ytuant-saddle and theback saddle-:of noveldesign -tofpermit free play therebetween without bindingor cramping.

Another object is to provide 'a saddle assembly inl-which the back saddle is completely nested within and shielded` kby :the trontisaddle lto .prevent lint.and'dustifromicollecting on'the bearings.

Another object is-` to .provide means on the saddle forreadily andl conveniently attaching improved .bearing .elements which may be removed when worn and replaced'by others ofthe samev type4 with the. substitution 'easily accomplished inthemill `without; 'the .use of tools.

,Another. object is-to `:provide improved. bearing elements of novel form constructedfrom anti.- friction materialy requiring no lubrication and resistant to-wear'to render them durable for longv periodsof use.

.Another object isto pro-videan improved type of: open bearing toprevent heating at the 'bearing surfacesk on the arbors4 ofthe. rolls.

-Anotherobjectis to provide a saddleassembly having interchangeable; parts to adapt it foruseY AFurther objects of the invention are set forth.`

inthe following specication vwhich describes a preferred form of construction of the parts of theY saddle assembly withv two alternative arrangements thereof as Iillustrated kby thefaccompanying drawings. In .the drawings:

i6 Claims. (Cl. 19%137) Y Figgl is a plan view-of asetl of top and bottom drafting rolls'shown as partlyvbroken away and illustrating the 'present improved saddle as applied to use therewith; A

` Fig. 2 is-a-sidejelevational view of thefsame, part-sectional on line 22-of Fig. l;

Fig. 3 isa transverse sectional viewY ofy the'for- Ward end of the front saddlevtaken on `line 3-3 of Fig. 1 and showingthe removable bearing element attached thereto-'vforlengagement with the arbor of the front rol-l;

Fig. 4 is a similar transversesectional view of both the front and back saddle Ataken on lined-'4 of Fig. 1 and showing the removable bearing element for the middle Iroll in contact with the arbor of' said roll; 1

Fig. 5 is asimilar transverse :sectional view of thev rearward end of the backsaddle taken on line 5--5 of Fig. 1 andshowing the removable bearing element forthe arborof the back. roll in contact therewith; v

Figzis abottoni` planviewiof'the. front saddle showing: the weight-'plate Ahoused therein and; connected thereto; v

Fig. 1 is atopplanviewoi' the .back saddle; Eig..8 is a bottomplanlview fxthe back saddle; Fig. 9 is affragmentary vlongitudinal sectional view ofthe; forepart of .the iront-.saddle showing onev of.V the iiangesfor attaching the front top roll bearing` element thereto;

Fig. 10V is a transverse sectional view oi the backsaddletaken on line lll--I 0 of Fig. '1;

Fig. 11v is a perspective view of the attachable bearing element forthe front roll; Fig. 12 is vaperspective view of the attachable bearing element'forj the middleroll; A

Fig. 13 isa perspective'view of the attachable bearing for the backrolhand Fig. .la is a. side elevationin longitudinal'section of anfalternative'arrangement'of thesaddle assembly for use without the middle ro1l.

Heretofore ithas beenv thezgeneral practice to employ saddles for weighting the top'rolls of machines for treating textile fibers, 'for example, spinning and drawing'framesiuwith theaparts. constructed of malleable or'castiron. In lmostcases the'bearings .or'the arbore-.of the top rolls comprise. either vrecessed or flat'gportionsof .the metal and the saddlev is formed'on ythe top with. oilpockets or cups and ducts leading 'therefrom to lubricate .thesebearings Such saddles are open tothe disadvantage of collecting'dust and lint inlthe oil pockets and .oil holes. which collection interfereslwith the properlubrication of the bearings and. results in increased Jfriction and severe ISTAT-ES i therefrom for replacement to extend the life ofv v `the saddle practically indefinitely.

In accordance with the present invention the` removable bearings for the saddle are constructed from a distinctive type of material having friction-reducing and extraordinary wear-resisting characteristics. For this purpose the invention contemplates the use of attachable bearing elements made wholly or in part of a material having a hardness substantially that of a Rockwell hardness of 90-95 on the M scale. One such material, for example, is a synthetic linear super polymer or synthetic linear `polyamide described in United States Letters Patent No. 2,130,948, is-

sued SeptemberZO, 1933120 C'arothers. lNo claim is made herein tothe polymerper se, the present invention being directed to a bearing element made in whole or in part from said polymer identiiied by the trade-name nylon. The bearing elements may be cast, molded or cut from a strip of the material,- the details of such method of manufacture being well known and therefore not herein described. l

Referring to Figs. 1 to 10, inclusive, the present improved saddle and its attachable bearings are herein shown as applied Ito a set of drafting rolls for spinning frames` such as illustratedin Figs. l and 2. The set of rolls comprises a botto-m front roll 2, Aa middle roll 3, and a back roll 4, with corresponding top rolls arranged thereabove for cooperation with the peripheries of the bottom rolls. Fig. 1 shows a front top Vroll '5, a middle top roll 6 and a back top roll 1,. and in accordance with the usual arrangementthebottom rollsare journaled in fixed bearings whilev the top rolls have end gudgeons slidably journaled in spaced slots in cap-bars. A representation of the capbars and journals for the rolls is eliminated from the present drawings for the sake of simplicity and clarity in 'the showing of the essential .parts of the invention. The top rolls 5, 6 and I comprise axially-aimed cylindrical hubs, a-Eb, (ia- Sb and 'IB-"Ib, respectively, constituting the rolls proper, with the hubs of veach pair connected by arbors 8, S and l0, respectively, that may be constructed integral with the hubs or formed by spindles or shafts eX-ten'dingthrough axial bores in .the hubs. The saddle assembly is arranged `above the top rolls and provided with bearings Vengaging the arbors 8, 9 andI. The-saddle assembly is constituted by a front saddle I6 and a back saddle I'I connected thereto for movement therewith and .both saddles are weighted to cause the rolls to bear on the fibers feeding between the peripheries `of the opposed top and bottom rolls. The saddle assembly is weighted by means of a stirrup I8 depending from the front saddle and connected to a lever carrying a weight hook at its ends with weights suspended thereon.

One feature of the present invention consists in constructing the saddle assembly from sheetmetal to adapt the parts to be stamped out and struck up in dies for the sake of economy in manufacture and to further provide a construc- 4 tion for enclosing and shielding the operative parts of the device from lint and dust. For this purpose the front saddle 1'6 is of hollow form having a substantially convex or dome-shaped top wall 29 reaching from the front throughout the greater portion of its length andextended at its rear lin a relatively fiatiA wallportion 2 i' terminat ingv in a"downwardlycurved end 22. The interor of the front saddle IB is enclosed by depending side walls or skirts 23 thus forming a hollow shell with its under side open and adapted to overlie and enclose the back saddle I1 as a protecting shield tomprevent the accumulation of lint and ldust onthe bearings and other parts.

' The top'of the front saddle I6 may be polished,

. plated, enameled or otherwise nlshed with a smooth surface not attractive to the lodgement of lint and dust thereon. At the forward end of the side walls 23 the metal is bent or folded inwardly to form relatively narrow fins or flanges 24 for attaching the front bearing element 35 thereto by engagement withits grooved sides in themanner as laterv explained.

Fastened Within the 'interior ofthe Vfront saddle IG and extending llongitudinally thereof is a weight-pressureplate 25 constructed from sheetmetal and arranged to bear on the back saddle I1 to apply pressure thereto for weighting the bearings for the middle and baclrtoprolls. As shown more particularly in Fig s..2 and 5, the weightplate 25 may beHsli-ghtly crownedV laterally with its rearward portion Welded or otherwise secured tothe flat top wall extension 2| vof the front saddle i6 and its forward end is bent upwardly at 26 and then forwardly to underlie the` crownedY wall 20 of the Afront saddle to Whichit is` suitably fastened by welding or otherwise: VReferring to Fig. 2 the weight-plate 25 is .provided with upstanding flanges 21 at its sides arranged in abutting relation to the side walls 2'3 of thefront saddle I6 to locate the weight-plate laterally therein and reinforce the whole structure. j The weight-plate 25 is formed with a longitudinally-extending slot comprising a wide portion 28VA towards its front end and extended in a narrow rportieri 28 at the rear as shown more particularly in Fig. 6'.' The forward wider slot-portion 2-8 provides an opening for receiving the end of the stirrup I3, shown in Fig. 2 as having a curved upperV end and pivotally attached to the front saddle I'S by a crosspin 30 extending .between the sides thereof and suitably secured. thereto.v The rearward,` narrower slot-portion 29 is designed to receive the connecting means for thebacklsaddle IFIV as later explained in detail. l

The back saddle: ...n iszaiscfcoristrirctedfrm.

sheet-metal with a top wall 'thslightlycrowned laterally as shown in Figs. 4 and 5, and'Nertical side wallsV 32 depending therefrom: '.At. their lower edges the side wa1ls32. are bent. or folded inwardly to provide longitudinally-'extending fins or flanges 33 and -34 Ifor engagement-with the grooved sides of bearing elements 36 and 3lforv the middle and' back rolls 6 and 1,res`pectively.

,Referring to Fig. 2, the top wall 3| -has down- The key adapt it:V to engage. through the narrower. islet# portion; 29 inrtheV weight-'plate 7.5, :being swelled outwardly .'atithe. top .in a roundedprotuberance 4Z l-widerlthan 'the "slot and .i forming a 'head :to prevent thev .withdrawal 'oil the; key .therefrom unless for .it .islturned at'ninety degrees utc aline it with. the. slot. Through. this last-described construction oflthel ioack'ss'addle 'l1 a noveland ingenious form of coupling is provided for connecting it with the front saddle I6 to permitlplay therebetween. That is-to say, theback saddle l1 is .connected tothe. vfront saddle I6 to provide free .play therebetween and allow relative rocking motion of th'eback saddle laterally and and longitudinally about its. connection therewithV without vany 'tendency to 'cramp or bind. Through. this .means ftheV frontsaddle IIB. rvand back saddle. l1 arey connected forurelativefadjust-k ment to conform '-*tovariations'in the location of themiddletop rol-lv 6 and the back top roll 1 andinsure proper contact'of the bearings'on their arbors 9 and t0, respectively.

Referring to Figs. 11,A .12l and 13, the bearing elements` 35., 36 and SIshown in. .perspective in these views are preferaloly constructed from a material having a hardness. substantially that of a Rockwell hardness of Eid-95 on theM scale, for example, nylon, as previously indicated. but they may be made of other self-lubricating materials if desired while retaining the advantage of easy attachment to the saddle. .Itihas been ydemonstrated, however, thatmaterial having Vsubstantially'the hardness: specified above is rpreferable since Vitrhas .the most. satisfactory bearing characteristics vand is. .extraordinarily resistant to wear, either of itself. or asregards. the roll arbor with which it engages. The phenomenaofwear may .beexplainedin theory asactually due in large part to the impactandconsequent `lerealzing .01T of minute protuberances at the interface of any hearing.. Nylon, however, being elastic and. tough,. and relatively soft, tends to spring away' from the metallic protuherances on .the arbor orshaft with Ywhichit engages instead of the protuberances being sheared off, thus resisting wear from the abrasive action.

Referring to Figs. l1l,'12 and. 13,`the present improved bearing elements 35, 36 and `31 are preferably constructed in the form of ilat pads or rectangular blocks of somewhat different shapes and dimensions to adapt them for appropriate location on the saddle in `accordance with the arrangement of the several top rolls. The Vfront bearing element. 35 may loe of generally rectangular shape and formed on its sides with narrow longitudinal 'grooves 45, see Fig. 11, for receiving the flanges 24 which Aproject inwardly from theside walls 23 of the fro-nt saddle IB, see Figs. 3 and 9'. It will be observed that the upper portion of the bearing element 35 is cut hacker recessed iat 46 to adapt it-lto receive the lower end of the downwardly-curved forward wall of the front saddle` 1.6 as shown more particularly in Fig. 2 `of the drawings. Asshown in this view and Fig. 1l the under face of the bearing element 35 is formed with an arcuate concavity 41 of a radius corresponding to the radius of the arbor 8 of the front roll 3 toprovide for vthe interiitting engagement of the bea-ring element therewith.

The hearingielement 3G for the middle topA roll `6 may be a-plain pad or block of .rectangular shape as shown-in Fig. 12 vwith longitudinallyextending groovesll o-nits sides for engagement4 with the ilanges 33V that project inwardl'yrom the. side'sLof theback saddle Il` 'at-.its yforward end',;see'Fig..-fi. .'I'hefhearing-element'36-,prefer ably. hasta .plane'lunder.'f.surface.vizitheutv any vconcavity therein fori.' engagement with'fthe `arbor 9 ofthe middle: roll. l;V thus adapting ittici-.variationsiin the.'spacing'btweenthe back roll' T and themiudierrcil: '.11 Y l ''fIrhe bearinglelement.31fifor fthe leackitopV roll maytake a's'till different formv suchv as `shown in' Fig. 13,.-being rectangularlinloutline and un-` dercut fat the. bottom'4 to Jprovide' two-depending lugs' 49 .and A511?lA adapted teT l,s'trad'dle the arbor Y l0 of 1the leack-topiroll f 1.a's shown in-Fig. 2'. VThe lugs'u49 'and 50 serveas means -forlpre'venting longitudinal displacement offthe-loack Vsaddle 1 1 as'fis.'afusualv arrangement-infthe prior art. VBetweenthelugs-49 aridi!!l the" under iside of the hearing A element' 3Tv vis; formed-'with 'la concavity 5 I conforming; to the; rieri-j;dieral surface of lthe arbor f llt olf-the .ha-clrrollv 1 Thefbearing `element 31' is provided with" grooves `52-on its-'sides for receiving the 'inwardly-bent Iiian'ges '3l vat' the rearward end of' the-back saddle l1, see Figs5; it being noted by reference' to Fig. 2'that*the downwardly-extending i"end walls 38 and l'39 on the saddle overlap the endsofthe two rhearing elements *35 vand tulvfte'locate lth'e'njr"y in lposition thereon.V p H As before stated, the bearing elements 35', L5t and 31 `may be constructedefrcm' nylon andbe either cast, molded ormacliir'ied'from atstock. Instead of making each'bearing elemententirely from the polymer itmay be of composite construction, that is', partly ofmetal or'other material. For example, eachlbearing element may have its upper part of brass `or'oth'er metal with a layer or *relatively thin rpad of nylonsecured to its under sideloy cementing or-otherwilse.

It will be understood thatwith bearing ele-V ments 'constructed of the'preferred specifiedmaterial they are attachable-to the saddle-by merely placing them betweenthe side walls thereof and sliding them; into position to engage the flanges with their lateral grooves; More specifically, the front bearing element 35 iss'imply placed between th'e side-walls 23 of thefront saddle i6 and slid forwardly to engage the ilanges 2'4 in its grooves 45. Likewise, :the middle 'bearing element 36 vis placed betweentlieside-walls of the back saddle l1 approximately centrallyA thereof and slid forwardly to engage the 'flanges 33with its grooves 48; and the bearing element 31 is similarly placed between lthe sidewalls of the back saddle l1 and'slid rearwardly to engage the flanges vliil'with its grooves52. The'grooves in the hearing elements are ipreferably of such width as-to providefor-their frictional engage-l ment with .theflanges on-the'sad'dlesso tl'oat"v the elementsv will 'beheld insecure vengagement therewith." Insome casesthegrooves Amay be tapered slightly 'from `hack to front to prevent the bearing elements fromv sliding forward underv the turning stress of the roll arbors. Inthsway the bearing elements may he securely vfastenedto the. saddlefassembly and positioned to cooperate with the Varhors of .the severalitop. rcbllsv whereof to' provide oillessbearings' havingfriction-reducing and wear-resisting characteristics tov adapt them for continuous. Yuse overlong,Y periods of time.` tShould any ofxthe hearing .elements .becomeworn to an appreciable .extent they may -be removed readily .by sliding fthemoutj of engage- V ment with thefflanges which holdthem inplace and thereafterfhe replaced by substitution of new ones. fDue, to; this o featurepof .improvement ythe saddle assembly becomes practically indestructible toprovide continuous service indefinitely.

- With: the bearing elements incorporated in the saddle assembly as shownin Fig. 2 of the drawings the top `rollsj are weighted by means of the stirrup i8 with a weight-leverrand Weights, not shown, cooperating in the usualv manner.` The bearings are protectedby the cover or shield formed ,bythe overlyingfront saddle i6 within which the bacio saddle Il is nested. Consequently, lint, dustfor otherextraneous matter is prevented from insinuating into the bearings or from collecting on other parts to interfere with their functioning. Due to the novel form of joint between the front saddle and back saddle, particularly as regardsthe angularly-related parts of the back saddlell and its key-and-slot connection with :the front saddle IE, the two saddle parts are free to rock relatively of each other both longitudinally and laterally to adjust their bearings for proper engagement with the arbors of the several rolls. As before noted, the lateral rocking action between the saddle parts is accommodated by the crowned form of the top wall 3| of the saddle I1 which underlies the crowned weight-plate in the saddle I6, see Fig. 4of the drawings. The weight applied through the stir-. rup I3- to the front saddle l5 is thus transmitted through the universal joint between the front saddle I6 and back saddle I1. to distribute it over the several top rolls as required for their proper cooperation 4with the bottom rolls.

y Referring to Fig. 14, this view illustrates a saddle assembly adapted for use with two sets of rolls without a middle set. For this purpose the same front saddle I6 may be employed with a simpler form of back saddle 55. The front saddle i6 is provided with thefront `bearing element 35 constructed as previously described and also embodying the same type of weight-plate 25. The back saddle consists of a dat plate portion 56 having an upwardly-extending key 51 formed with a rounded head 58 for holding it in connection with the front saddle by its engagement through the narrow portion 29 of the slot in the weight-plate. The rearward portion of the back saddle 55 is formed with side walls 59 folded downwardly therefrom and embodying inwardlyprojecting anges 6D, indicated by dotted lines in Fig. 14, for engagement with a back bearing element ,6| whichl is of substantially the same form as the bearing element 31 previously described but may beof shorter length. As herein shown the weight is applied to the front saddle I6 by the stirrup I8 which is reversed in position so that its upper curved end bows outwardly at the rear.l It will be observed that the presenty improvementsprovide a saddle construction for use with diiferent roll arrangements, that is with the front saddle adapted interchangeably for all uses. Thus, a change from one system to another may be made by simply substituting a different type of back saddle for use with the same front saddle.

It has been explained that the smooth exterior surface of the'front saddle guards against the lodgement thereon of lint and dust the nested arrangement of the back saddle therein shields the bearings -to prevent theV insinuation of lint and dust therein and` its collection on the parts to interfere with their r'proper functioning. The sheet-metal` form of-con'structionV of the parts of the saddle assembly provides for economical cost of manufacture i by the employment of stamping` and formingV operations in dies. As a most important advantage, the provision of bearing elements of the present type 'on the saddle avoids the need for lubrication and reduces friction and wear to prolong the Vlife of the saddle Aand the roll bearings practicallyindefinitely. The novel means for ready and con-g venient attachment of the bearing elementson the saddlek and their removal therefrom adapts them for replacement to further extend the life of the whole saddle assembly for indefinite periods.

The present plain or open type bearing, such as herein described, is preferable for the use of nylon due to the fact that this material of ite` self is a poor conductor of heat. With the open nylon bearing applied to the saddle the greater portion of the rotating arbor of the roll is `exposed to the atmosphere and thus will run cool. v- While the invention is herein shown as embodied in a preferred form of construction and adapted for use with two different systems of spinning, it is to be understood that other variations may be made in the form and arrangement of the parts and the type of material used in the construction of the saddle and its bearings withont departing from the spirit of the invention or the scope of the appended claims. Therefore, without limiting ourselves in this respect, we claim:

1. A saddle assembly for weighting the top rolls of textile machines comprising a front saddle formed with a crowned top wall at its forward portion and a relatively nat portion extending rearwardly therefrom, a pressure-plate extending longitudinally within the front saddle with its forward end engageable with the crowned top wall thereof and its rearward end engaging the rearward extension thereof, said pressure-plate formed with a longitudinal slot, a back saddle formed of sheet-metal with its top wall inclined downwardly from the center towards its ends, and a key projecting upwardly from the center of the back saddle through said slot in the pressure-plate with an enlargement at its upper end for connecting the back saddle to the front saddle to allow play therebetween, said saddles provided with bearings engageable with the arbors of the several top rolls.

2. A saddle assembly for weighting the top rolls of textile machines comprising a front saddle constructed of sheet-metal in hollow form open on its under side, a slotted pressure-plate fastened within the front saddle extending longitudinally thereof and of concavo-convex form in cross-section, a back saddle having a top wall of concavo-convex form in cross-section engageable with the concaved bottom of the pressure-plate, and a key projecting upwardly from said back saddle through the slot in the pressure-plate and formed with an enlargement at its upper end to normally prevent its release from the slot in thepressure-plate, said front and back saddlesprovided with bearings for engagement withthe arbors of the several top rolls.

3. Asaddle assembly for weighting the top rolls of textile machines comprising a front saddle of hollow sheet-metal construction having a crownedv top and depending sides, a separate sheet-metal pressure-plate positioned within said hollow front saddle extending longitudinally thereof and having an upwardly-projecting portion at its forward end engaging against the under side of the crowned top of the front saddle,`

a back saddle having a top wall inclined downwardly from its center towards its ends, said back saddle located beneath the pressure-plate with its central raised portion bearing against the under side thereof, bearings on the front and back saddle for engaging the arbors of the several top rolls, and a stirrup connected to the front saddle to weight the latter and transmit pressure to the pressure-plate to weight the back saddle.

4. A saddle assembly for weighting the top rolls of textile machines comprising a front saddle of hollow sheet-metal construction having a crowned top and depending sides, a separate sheet-metal pressure-plate positioned within said front saddle extending longitudinally thereof and having an upwardly-projecting portion at its forward end in contact with the under side of the crowned top of the front saddle, and a back saddle having a top wall inclined downwardly from its center towards its ends with its central raised portion bearing against the under side of the pressure-plate, said back saddle having a key projecting upwardly through an opening in the pressure-plate to hingedly connect it thereto.

5. A saddle assembly for weighting the top rolls of textile machines comprising a front saddle constructed of sheet-metal in hollow form having a top wall with spaced parallel walls extending downwardly at its sides and provided with relatively short portions of the metal at the front folded inwardly therefrom to project toward each other in the form of flanges, and a bearing element consisting in a block of frictionreducing material scored on its opposite sides with longitudinal grooves for engagement with said flanges to support said bearing elementv nxedly on the saddle embraced between the side walls thereof, said grooves in the bearing element being of a width to cause the flanges to frictionally engage the sides thereof to adapt said element to be slid into place on the saddle while permitting its slidable removal therefrom for repair or replacement without the use of tools.

6. A saddle assembly for the top rolls of textile machines comprising a front saddle constructed of sheet-metal shaped to provide a top wall with vertical side walls depending therefrom, said side walls formed at the bottom with relatively short flanges folded inwardly to project toward each other, a bearing element consisting in a block of friction-reducing material scored on its sides to form narrow grooves dimensioned to engage frictionally with the inturned flanges on the side Walls of the front saddle by sliding said bearing element between said side walls, a sheetmetal back saddle hingedly connected to said front saddle and shaped with a top wall and depending. side walls, said last-named side walls formed at the bottom with relatively short flanges folded inwardly to project toward each other, and a block-like bearing element constructed of friction-reducing material with narrow grooves in its sides frictionally engageable with the flanges on the sides of the back saddle to adapt said bearing element to be slidably mounted thereon and readily removable therefrom for repair or replacement without the use of tools.

LOUIS M. COTCHETT. ROBERT RULON-MILLER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 347,910 Young et al Aug. 24, 1886 394,124 Metcalf Dec. 4, 1888 784,276 Pierce Mar. 7, 1905 1,176,756 Houghton Mar. 28, 1916 1,218,658 Houghton Mar. 13, 1917 1,238,673 Houghton Aug. 28, 1917 2,075,484 Truslow Mar. 30, 1937 2,246,086 Austin June 17, 1941 2,496,765 Williams Feb. 7, 1950 FOREIGN PATENTS Number Country Date 203,017 Great Britain Aug. 28, 1923 

